The Greater Weaver (_Trachinus draco_) lives at the bottom of deep water, and is often dredged up in the trawl. Some fishermen call it the Sting Bull, and always take the precaution of cutting off the poisonous spines before disposing of the fish. It lives on the bottom with its mouth and eyes directed upward, always in readiness to seize its unwary prey, and the sharp spines of the dorsal fins are kept erect for the purpose of promptly attacking approaching foes. Its mouth and palate are armed with sharp teeth which render the escape of its prey almost impossible. The smaller species (_T. vipera_) seldom exceeds six inches in length. It lives in shallow water on sandy coasts, with dorsal spines erect; and the wounds it produces on the unprotected feet of bathers are often exceedingly painful on account of the injected poison, which also causes the part to swell and turn to a dark purple colour. The remaining important families, although they contain well-known British food-fishes, do not include littoral species, and for this reason we shall pass them over with but brief notice. The Mackerel (_Scomber vernalis_) belongs to the family _Scomberidæ_, and is so well known that no description need be given for the purposes of identification. We have already referred to it as a beautiful illustration of protective colouring, its upper surface resembling the ripples of a deep green sea and the lower the brightness of the sky. Mackerel swim in shoals in the open sea, pursuing and devouring the fry of herrings and other fish; and in order that they may be enabled to cover enormous distances their muscles are richly supplied with blood. This not only gives a pinkish colour to the flesh, but results in a greater amount of oxidation and the maintenance thereby of a body temperature several degrees higher than that of the surrounding water. We would also call attention to the five or six small fins behind the dorsal and anal fins as characteristic of the _Scomberidæ_. Our next family (the _Cyttidæ_) contains the John Dory (_Zeus-faber_), concerning which some superstitions are still prevalent in parts. It is brightly coloured, but not graceful in form, and is often caught in large numbers off the coasts of Devon and Cornwall. Some fishermen call it the Cock, on account of the crest on the back; while others know it as St. Peter’s Fish, and will point out the impression of the Apostle’s finger on each side--a black spot surrounded by a light ring. The Horse Mackerel (_Caranx trachurus_) is found principally in the same parts, where it devours the fry of other fishes. It is not a very close relative of the common mackerel, but belongs to a distinct family (_Carangidæ_), of which it is the only British representative. It is a carnivorous fish, easily distinguished from _Scomber_ by its conical teeth, as well as by the bony plates of the lateral line, the posterior of which are keeled or spined.